net/mlx5e: bind() always returns EINVAL with XDP_ZEROCOPY

[Kal Cutter Conley <kal.conley@xxxxxxxxxxx>]

Hello,
I am testing the mlx5e driver with AF_XDP. When I specify
XDP_ZEROCOPY, bind() always returns EINVAL. I observe the same problem
with the xdpsock sample:

sudo samples/bpf/xdpsock -r -i dcb1-port1 -z
samples/bpf/xdpsock_user.c:xsk_configure_socket:322: errno:
22/"Invalid argument"

Without XDP_ZEROCOPY, everything works as expected. Is this a known
issue/limitation? I expected this to be supported looking at the
code/commit history.

Thanks,
Kal